Creation of a Prognostic Index for Spine Metastasis to Stratify Survival in Patients Treated With Spinal Stereotactic Radiosurgery: Secondary Analysis of Mature Prospective Trials

Dose-intensified SBRT for vertebral oligometastases: results from a prospective clinical trial

PURPOSE

To prospectively evaluate safety and efficacy of dose-intensified multifraction SBRT using a simultaneous-integrated boost concept for vertebral oligometastases.

MATERIAL AND METHODS

Data from 128 patients with 143 vertebral oligometastases (≤5 distant metastases in total) treated with dose-intensified SBRT (48.5 Gy/10 [with epidural involvement] or 40 Gy/5 [without epidural involvement]) in the randomized and non-randomized arms of a phase 3 clinical trial conducted at 18 international centers between 2016 and 2023 were analyzed.

RESULTS

The median age of all patients was 68 years; 77 patients (60.2%) had breast and prostate cancer. Of 143 vertebral metastases, 23 (16.1%) and 22 metastases (15.4%) had epidural and paraspinal tumor involvement, respectively. The median follow-up time was 24 months. At 2 years, cumulative incidence of local failure (4 failures) was 5.3%. There were 4 (2.8%) baseline and 8 (5.6%) de novo vertebral compression fractures (VCFs). Two-year OS was 82.2% (95% CI, 74.9-89.6%). There was no grade ≥ 4 adverse events (AE) and the crude rate of grade 3 AEs was 5.5%; no myelopathy or plexopathy was observed. On multivariate analysis, only non-breast or non-prostate cancer (HR, 7.91; 95%, CI 1.79-35.03; 2-sided P = 0.01) were found to be prognostic for adverse OS. No prognostic factors for VCF were identified. Epidural and paraspinal involvement were not found to be prognostic for treatment outcome.

CONCLUSIONS

Dose-intensified SBRT for vertebral oligometastases is effective and safe, even in high-risk patients with epidural or paraspinal involvement.

Racial Disparities in Patients with Metastatic Tumors of the Spine: A Systematic Review

OBJECTIVE

Disparities in access and delivery of care have been shown to disproportionately affect certain racial groups. Studies have been conducted to assess these disparities within the spinal metastasis population, but the extent of their effects in the setting of other socioeconomic measures remains unclear. The purpose of this study was to perform a systematic review to understand the effect of racial disparities on outcomes in patients with metastatic spine disease.

METHODS

The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed, where a comprehensive online search was performed using Pubmed, Medline, Web of Science, Cochrane, Embase, and Science Direct using MeSH terms related to metastatic spine tumor surgery and racial disparities up to February 2023. Two independent reviewers screened and analyzed articles to include studies assessing the following primary outcomes: clinical presentation, treatment type, postoperative complications, readmission, reoperation, survival and/or mortality, length of hospital stay, discharge disposition, and advance care planning.

RESULTS

A total of 13 studies were included in final analysis; 12 were retrospective cohort studies (Level of evidence III) and 1 was a prospective study (Level of evidence II). Postoperative complications were the most studied outcome in 46% of studies (6 of 13), followed by survival in 31% (4 of 13), and treatment type also in 31% (4 of 13). Overall, race was found to be significantly associated with at least one evaluated outcome in 69% of studies (9 of 13). Racial disparities were found in the incidence of cord compression, non-routine discharge, and treatment type in patients with metastatic spine disease. No differences were found on rates of post-operative ambulation, advance care planning, readmission, or survival; inconsistent results were seen for postoperative complications and length of stay. Nine studies (69%) included at least one other measure of socioeconomic status in multivariate analysis, with the two most common being insurance type and income.

CONCLUSIONS

Although some studies suggest race to be associated with presenting characteristics, treatment type and outcome of patients with spinal metastases, there was significant variability in the inclusion of measures of socioeconomic status in study analyses. As such, the association between race and outcomes in oncologic spine surgery remains unclear.

Validation of the prognostic index for spine metastasis (PRISM) for stratifying survival in patients treated with spinal stereotactic body radiation

PURPOSE

The Prognostic Index for Spinal Metastasis (PRISM) is a scoring system derived from prospective data from a single institution that stratifies patients undergoing spine stereotactic radiosurgery (SSRS) for spinal metastases into subgroups by overall (OS). We sought to further demonstrate its generalizability by performing validation with a large dataset from a second high-volume institution, Mayo Clinic.

METHODS AND MATERIALS

Eight hundred seventy-nine patients-424 from Mayo Clinic and 455 from MD Anderson Cancer Center (MDACC)-who received SSRS between 2007 and 2019 were identified. Patients were stratified by PRISM criteria, and overall survival (OS) for the PRISM groups for each cohort was compared using Kaplan-Meier estimations and univariate Cox proportional analyses. Model calibration and concordance indices (C-indices) were calculated for each cohort to assess the quality of the scoring system.

RESULTS

Patient and tumor characteristics varied significantly between both cohorts including histology, sex, performance status, and number of organs involved (all P < 0.001). Median OS was 30.3 and 22.1 months for the Mayo and MDACC cohorts, respectively. Kaplan-Meier survival curves revealed robust separation between prognostic groups within both cohorts. The Mayo cohort showed median OS of 57.1, 37.0, 23.7, and 8.8 months for Groups 1, 2, 3, and 4, respectively. Univariate analysis revealed hazard ratios of 3.0 (95 % confidence interval [CI], 1.9-4.9), 5.2 (95 % CI, 3.2-8.3), and 12.9 (95 % CI, 7.8-21.4) for groups 2, 3 and 4, respectively all P < 0.001). The C-indices were 0.69 and 0.66 for the unstratified and stratified scores for the Mayo cohort, and 0.70 and 0.68 for the MDACC cohort, respectively.

CONCLUSION

These data demonstrate robust validation of the PRISM score to stratify OS in patients treated with SSRS by a large external cohort, despite substantial differences among the cohorts. Overall, the PRISM scoring may help guide optimal treatment selection for patients with spine metastases.

Predictors of Clavien-Dindo Grade III-IV or Grade V Complications after Metastatic Spinal Tumor Surgery: An Analysis of Sociodemographic, Socioeconomic, Clinical, Oncologic, and Operative Parameters

The rate of major complications and 30-day mortality after surgery for metastatic spinal tumors is relatively high. While most studies have focused on baseline comorbid conditions and operative parameters as risk factors, there is limited data on the influence of other parameters such as sociodemographic or socioeconomic data on outcomes. We retrospectively analyzed data from 165 patients who underwent surgery for spinal metastases between 2012-2023. The primary outcome was development of major complications (i.e., Clavien-Dindo Grade III-IV complications), and the secondary outcome was 30-day mortality (i.e., Clavien-Dindo Grade V complications). An exploratory data analysis that included sociodemographic, socioeconomic, clinical, oncologic, and operative parameters was performed. Following multivariable analysis, independent predictors of Clavien-Dindo Grade III-IV complications were Frankel Grade A-C, lower modified Bauer score, and lower Prognostic Nutritional Index. Independent predictors of Clavien-Dindo Grade V complications) were lung primary cancer, lower modified Bauer score, lower Prognostic Nutritional Index, and use of internal fixation. No sociodemographic or socioeconomic factor was associated with either outcome. Sociodemographic and socioeconomic factors did not impact short-term surgical outcomes for metastatic spinal tumor patients in this study. Optimization of modifiable factors like nutritional status may be more important in improving outcomes in this complex patient population.

Stereotactic body radiation therapy for bone oligometastases

Stereotactic body radiation therapy is effective for the local management of oligometastases (at most five metastases) with a benefit in survival and local control. Most studies on the management of oligometastases focus on all oligometastatic sites in primary cancer and very few focus on a single oligometastatic site. In particular, there are few data on bone oligometastases, which represent one of the preferred sites for secondary cancer locations. This article focuses on the benefit of stereotactic radiotherapy for bone oligometastases of all cancers by histological types, and reviews the results of major studies in this field.

Prognostication for Patients Receiving Palliative Radiation Therapy

Estimation of patient prognosis plays a central role in guiding decision making for the palliative management of metastatic disease, and a number of statistical models have been developed to provide survival estimates for patients in this context. In this review, we discuss several well-validated survival prediction models for patients receiving palliative radiotherapy to sites outside of the brain. Key considerations include the type of statistical model, model performance measures and validation procedures, studies' source populations, time points used for prognostication, and details of model output. We then briefly discuss underutilization of these models, the role of decision support aids, and the need to incorporate patient preference in shared decision making for patients with metastatic disease who are candidates for palliative radiotherapy.

Development and validation of a unifying pre-treatment decision tool for intracranial and extracranial metastasis-directed radiotherapy

Background

Though metastasis-directed therapy (MDT) has the potential to improve overall survival (OS), appropriate patient selection remains challenging. We aimed to develop a model predictive of OS to refine patient selection for clinical trials and MDT.

Patients and methods

We assembled a multi-institutional cohort of patients treated with MDT (stereotactic body radiation therapy, radiosurgery, and whole brain radiation therapy). Candidate variables for recursive partitioning analysis were selected per prior studies: ECOG performance status, time from primary diagnosis, number of additional non-target organ systems involved (NOS), and intracranial metastases.

Results

A database of 1,362 patients was assembled with 424 intracranial, 352 lung, and 607 spinal treatments (n=1,383). Treatments were split into training (TC) (70%, n=968) and internal validation (IVC) (30%, n=415) cohorts. The TC had median ECOG of 0 (interquartile range [IQR]: 0-1), NOS of 1 (IQR: 0-1), and OS of 18 months (IQR: 7-35). The resulting model components and weights were: ECOG = 0, 1, and &gt; 1 (0, 1, and 2); 0, 1, and &gt; 1 NOS (0, 1, and 2); and intracranial target (2), with lower scores indicating more favorable OS. The model demonstrated high concordance in the TC (0.72) and IVC (0.72). The score also demonstrated high concordance for each target site (spine, brain, and lung).

Conclusion

This pre-treatment decision tool represents a unifying model for both intracranial and extracranial disease and identifies patients with the longest survival after MDT who may benefit most from aggressive local therapy. Carefully selected patients may benefit from MDT even in the presence of intracranial disease, and this model may help guide patient selection for MDT.

Development and validation of a recursive partitioning analysis-based pretreatment decision-making tool identifying ideal candidates for spine stereotactic body radiation therapy

BACKGROUND

This study was aimed at developing and validating a decision-making tool predictive of overall survival (OS) for patients receiving stereotactic body radiation therapy (SBRT) for spinal metastases.

METHODS

Three hundred sixty-one patients at one institution were used for the training set, and 182 at a second institution were used for external validation. Treatments most commonly involved one or three fractions of spine SBRT. Exclusion criteria included proton therapy and benign histologies.

RESULTS

The final model consisted of the following variables and scores: Spinal Instability Neoplastic Score (SINS) ≥ 6 (1), time from primary diagnosis < 21 months (1), Eastern Cooperative Oncology Group (ECOG) performance status = 1 (1) or ECOG performance status > 1 (2), and >1 organ system involved (1). Each variable was an independent predictor of OS (p < .001), and each 1-point increase in the score was associated with a hazard ratio of 2.01 (95% confidence interval [CI], 1.79-2.25; p < .0001). The concordance value was 0.75 (95% CI, 0.71-0.78). The scores were discretized into three groups-favorable (score = 0-1), intermediate (score = 2), and poor survival (score = 3-5)-with 2-year OS rates of 84% (95% CI, 79%-90%), 46% (95% CI, 36%-59%), and 21% (95% CI, 14%-32%), respectively (p < .0001 for each). In the external validation set (182 patients), the score was also predictive of OS (p < .0001). Increasing SINS<zaq;6> was predictive of decreased OS as a continuous variable (p < .0001).

CONCLUSIONS

This novel score is proposed as a decision-making tool to help to optimize patient selection for spine SBRT. SINS may be an independent predictor of OS.

Could conventionally fractionated radiation therapy coupled with stereotactic body radiation therapy improve local control in bone oligometastases?

PURPOSE

To describe clinical outcomes of stereotactic body radiation therapy (SBRT) applied alone or as a boost after a conventionally fractionated radiation therapy (CFRT) for the treatment of bone oligometastases.

MATERIAL AND METHODS

This retrospective cohort study included patients treated with SBRT from January 2007 to December 2015 in the Institut de cancérologie de Lorraine in France. The inclusion criteria involved adults treated with SBRT for one to three bone metastases from a histological proven solid tumor and a primary tumor treated, an Eastern Cooperative Oncology Group (ECOG) score inferior or equal to 2. Local control (LC), overall survival (OS), progression free survival (PFS), bone progression incidence (BPI), skeletal related events free survival (SRE-FS), toxicity and pain response were evaluated.

RESULTS

Forty-six patients and 52 bone metastases were treated. Twenty-three metastases (44.2%) received SBRT alone mainly for non-spine metastases and 29 (55.8%) a combination of CFRT and SBRT mainly for spine metastases. The median follow-up time was 22months (range: 4-89months). Five local failures (9.6%) were observed and the cumulative incidences of local recurrence at 1 and 2years respectively were 4.4% and 8% with a median time of local recurrence of 17months (range: 4-36months). The one- and two-years OS were 90.8% and 87.4%. Visceral metastasis (HR: 3.40, 95% confidence interval [1.10-10.50]) and a time from primary diagnosis (TPD)>30months (HR: 0.22 [0.06-0.82]) were independent prognostic factors of OS. The 1 and 2years PFS were 66.8% and 30.9% with a median PFS time of 18months [13-24]. The one- and two-years BPI were 27.7% and 55.3%. In multivariate analysis, unfavorable histology was associated with worse BPI (HR: 3.19 [1.32-7.76]). The SRE-FS was 93.3% and 78.5% % at 1 and 2years. The overall response rate for pain was 75% in the evaluable patients (9/12). No grade≥3 toxicity nor especially no radiation induced myelopathy (RIM), two patients developed asymptomatic vertebral compression fractures.

CONCLUSION

The sole use of SBRT or its association with CFRT is an efficient and well-tolerated treatment that allows high LC for bone oligometastases.

Stereotactic body radiotherapy versus conventional radiotherapy for painful bone metastases: a systematic review and meta-analysis of randomised controlled trials

BACKGROUND

Stereotactic body radiotherapy (SBRT) is a promising approach in treating painful bone metastases. However, the superiority of SBRT over conventional external beam radiotherapy (cEBRT) remains controversial. Therefore, this systematic review and meta-analysis of randomised controlled trials was conducted to compare SBRT and cEBRT for the treatment of bone metastases.

METHODS

A search was conducted using PubMed on January 22, 2022, with the following inclusion criteria: (i) randomised controlled trials comparing SBRT with cEBRT for bone metastases and (ii) endpoint including pain response. Effect sizes across studies were pooled using random-effects models in a meta-analysis of risk ratios.

RESULTS

A total of 1246 articles were screened, with 7 articles comprising 964 patients (522 and 442 patients in the SBRT and cEBRT arms, respectively) meeting the inclusion criteria. The overall pain response (OR) rates of bone metastases at 3 months were 45% and 36% in the SBRT and cEBRT arms, respectively. The present analyses showed no significant difference between the two groups. In four studies included for the calculation of OR rates of spinal metastases at three months, the OR rates were 40% and 35% in the SBRT and cEBRT arms, respectively, with no significant difference between the two groups. The incidence of severe adverse effects and health-related quality of life outcomes were comparable between the two arms.

CONCLUSIONS

The superiority of SBRT over cEBRT for pain palliation in bone metastases was not confirmed in this meta-analysis. Although SBRT is a standard of care for bone metastases, patients receiving SBRT should be selected appropriately.

Stereotactic Body Radiation Therapy (SBRT) for Spinal Metastases: Real-world Outcomes From an International Multi-institutional SBRT Registry

OBJECTIVE

The objective of this study was to compare clinical outcomes following single fraction versus fractionated stereotactic body radiotherapy (SBRT) for spinal metastases.

MATERIALS AND METHODS

A multi-institutional registry was queried for patients with spinal metastases treated with single-fraction or fractionated SBRT. Potential predictive factors of local control (LC) and overall survival were evaluated. Pretreatment and posttreatment Visual Analog Scale scores were analyzed to examine initial and durable pain responses and complete response (CR) rates. Logistic regression was utilized to assess potential correlations between pain response, biologically effective dose (BED), and fractionation.

RESULTS

Four hundred sixty-six patients with 514 lesions treated with SBRT were identified; 209 and 104 lesions had information on LC and pain, respectively. The median pain score of patients with symptoms was 6 (range: 3 to 10). The median follow-up was 8.9 months (range: 0.4 to 125.5 mo). Utilizing Karnofsky Performance Score, age, and primary site (lung and/or nonbreast), 1-year overall survival rates were 76.1%, 59.1%, 54.9%, 37.2%, and 23.5% for patients with 0 to 4 of these factors, respectively (P<0.0001). One- and 2-year LC rates were 79.9% and 73.6%, respectively. Eighty-six patients (82.7%) had an initial pain response with a median decline of 3.5 and a CR rate of 47.1%. Sixty-five patients (62.5%) had a durable pain response with a median decline of 2 and a CR rate of 20.2%. Higher initial CR rates were observed with BED10 ≥51 Gy10 (58.7% vs. 37.9%; P=0.04).

CONCLUSIONS

Following SBRT, encouraging palliative responses with >80% and 60% of patients having initial and durable pain responses, respectively. Dose escalation may result in improved initial CR rates. Performance status, age, and primary histology are factors to consider in the absence of pain.

Cost-effectiveness of treatment strategies for spinal metastases

PURPOSE

We analyze the cost-effectiveness of standard palliative external beam radiation (EBRT, 8 Gy in 1 fraction), stereotactic body radiation therapy (SBRT, 24 Gy in 2 fractions), and radiofrequency ablation (RFA) for painful spinal metastases. Single-fraction SBRT (delivering 24 Gy) is also assessed.

METHODS AND MATERIALS

A Markov state transition model was constructed. Key model parameters were derived from prospective clinical trial data. Strategies were compared using the incremental cost-effectiveness ratio (ICER), with effectiveness in quality-adjusted life years (QALYs) and a willingness-to-pay (WTP) threshold of $100,000 per QALY gained. Costs included both hospital and professional costs using 2020 Medicare reimbursement.

RESULTS

The base case demonstrated that 2-fraction SBRT was not cost-effective compared to single-fraction EBRT, with an ICER of $194,145/QALY gained. RFA was a dominated treatment strategy (more costly and less effective) in this model. Probabilistic sensitivity analysis demonstrated that EBRT was favored in 66% of model iterations. If median survival were improved after SBRT, two-fraction SBRT became cost-effective, with ICER of $80,394, $57,062, and $47,038 for 3, 6, and 9-month improvements in survival. Because two-fraction SBRT data reported 18% of patients with indeterminant pain response at 3 months, and two-fraction SBRT is infrequently used in clinical practice, single-fraction SBRT data was also assessed. Single-fraction SBRT delivering 24 Gy was cost-effective compared to single-fraction EBRT, with an ICER of $92,833/QALY gained.

CONCLUSIONS

For appropriately chosen patients, single-fraction SBRT is more cost-effective than conventional EBRT or RFA. Conventional EBRT remains a cost-effective treatment for patients with poor expected survival.

Prognostic Factors Associated With Surviving Less Than 3 Months vs Greater Than 3 Years Specific to Spine Stereotactic Body Radiotherapy and Late Adverse Events

BACKGROUND

Patient selection is critical for spine stereotactic body radiotherapy (SBRT) given potential for serious adverse effects and the associated costs.

OBJECTIVE

To identify prognostic factors associated with dying within 3 mo, or living greater than 3 yr, following spine SBRT, to better inform patient selection.

METHODS

Patients living ≤3 mo after spine SBRT and >3 yr after spine SBRT were identified, and multivariable regression analyses were performed. We report serious late toxicities observed, including vertebral compression fractures (VCF) and plexopathy.

RESULTS

A total of 605 patients (1406 spine segments) were treated from 2009 to 2018. A total of 51 patients (8.4%) lived ≤3 mo, and 79 patients (13%) survived >3 yr. Significant differences in baseline features were observed. On multivariable analysis, nonbreast/prostate primaries (odds ratio [ORs]: 28.8-104.2, P = .0004), eastern cooperative oncology group (ECOG) ≥2 (OR: 23.7, 95% CI: 3.2-177, P = .0020), polymetastatic disease (OR: 6.715, 95% CI: 1.89-23.85, P = .0032), painful lesions (OR: 3.833-8.898, P = .0118), and paraspinal disease (OR: 2.874, 95% CI: 1.118-7.393, P = .0288) were prognostic for ≤3 mo survival. The 3- and 5-yr rates of VCF were 10.4% and 14.4%, respectively, and 3- and 5-yr rates of plexopathy were 2.2% and 5.1%, respectively. A single duodenal perforation was observed, and there was no radiation myelopathy events.

CONCLUSION

Shorter survival after spine SBRT was seen in patients with less radiosensitive histologies (ie, not breast or prostate), ECOG ≥2, and polymetastatic disease. Pain and paraspinal disease were also associated with poor survival. Fractionated spine SBRT confers a low risk of late serious adverse events.

Patient-Reported Outcomes as Independent Prognostic Factors for Survival in Oncology: Systematic Review and Meta-Analysis

OBJECTIVES

Assessment of patient-reported outcomes (PROs) in oncology is of critical importance because it provides unique information that may also predict clinical outcomes.

METHODS

We conducted a systematic review of prognostic factor studies to examine the prognostic value of PROs for survival in cancer. A systematic literature search was performed in PubMed for studies published between 2013 and 2018. We considered any study, regardless of the research design, that included at least 1 PRO domain in the final multivariable prognostic model. The protocol (EPIPHANY) was published and registered in the International Prospective Register of Systematic Reviews (CRD42018099160).

RESULTS

Eligibility criteria selected 138 studies including 158 127 patients, of which 43 studies were randomized, controlled trials. Overall, 120 (87%) studies reported at least 1 PRO to be statistically significantly prognostic for overall survival. Lung (n = 41, 29.7%) and genitourinary (n = 27, 19.6%) cancers were most commonly investigated. The prognostic value of PROs was investigated in secondary data analyses in 101 (73.2%) studies. The EORTC QLQ-C30 questionnaire was the most frequently used measure, and its physical functioning scale (range 0-100) the most frequent independent prognostic PRO, with a pooled hazard ratio estimate of 0.88 per 10-point increase (95% CI 0.84-0.92).

CONCLUSIONS

There is convincing evidence that PROs provide independent prognostic information for overall survival across cancer populations and disease stages. Further research is needed to translate current evidence-based data into prognostic tools to aid in clinical decision making.

Spine stereotactic radiosurgery for metastatic thyroid cancer: a single-institution experience

OBJECTIVE

Patients with metastatic thyroid cancer have prolonged survival compared to those with other primary tumors. The spine is the most common site of osseous involvement in cases of metastatic thyroid cancer. As a result, obtaining durable local control (LC) in the spine is crucial. This study aimed to evaluate the efficacy of spine stereotactic radiosurgery (SSRS) in patients with metastatic thyroid cancer.

METHODS

Information on patients with metastatic thyroid cancer treated with SSRS for spinal metastases was retrospectively evaluated. SSRS was delivered with a simultaneous integrated boost technique using single- or multiple-fraction treatments. LC, defined as stable or reduced disease volume, was evaluated by examining posttreatment MRI, CT, and PET studies.

RESULTS

A total of 133 lesions were treated in 67 patients. The median follow-up duration was 31 months. Dose regimens for SSRS included 18 Gy in 1 fraction, 27 Gy in 3 fractions, and 30 Gy in 5 fractions. The histology distribution was 36% follicular, 33% papillary, 15% medullary, 13% Hurthle cell, and 3% anaplastic. The 1-, 2-, and 5-year LC rates were 96%, 89%, and 82%, respectively. The median overall survival (OS) was 43 months, with 1-, 2-, and 5-year survival rates of 86%, 74%, and 44%, respectively. There was no correlation between the absolute biological equivalent dose (BED) and OS or LC. Patients with effective LC had a trend toward improved OS when compared to patients who had local failure: 68 versus 28 months (p = 0.07). In terms of toxicity, 5 vertebral compression fractures (2.8%) occurred, and only 1 case (0.6%) of greater than or equal to grade 3 toxicity (esophageal stenosis) was reported.

CONCLUSIONS

SSRS is a safe and effective treatment option with excellent LC and minimal toxicity for patients with metastatic thyroid cancer. No association with increased radiation dose or BED was found, suggesting that such patients can be effectively treated with reduced dose regimens.

Spine stereotactic radiosurgery for metastases from hepatobiliary malignancies: patient selection using PRISM scoring

OBJECTIVE

Dose escalation via stereotactic radiation therapy techniques has been necessary for hepatobiliary malignancies in the primary and oligometastatic setting, but such dose escalation is challenging for spine metastases due to spinal cord proximity. Here, we investigate the role of spine stereotactic radiosurgery (SSRS) in the management of such metastases.

METHODS

We retrospectively reviewed patients treated with SSRS to spinal metastases from hepatobiliary malignancies between 2004 and 2017 at our Institution. We used the Kaplan-Meier method to calculate overall survival (OS) and local control (LC) and Cox regression analysis to identify factors associated with disease-related outcomes.

RESULTS

We identified 28 patients treated to 43 spinal metastases with SSRS for either HCC or cholangiocarcinoma. The 1-year LC and OS were 85% and 23%, respectively. The median time to death was 6.2 months, while median time to local failure was not reached. Tumor volume > 60 cc (SHR 6.65, p = 0.03) and Bilsky ≥ 1c (SHR 4.73, p = 0.05) predicted for poorer LC, while BED₁₀ > 81 Gy trended towards better local control (SHR 4.35, p = 0.08). Child-Pugh Class (HR 3.02, p = 0.003), higher PRISM Group (HR 3.49, p = 0.001), and systemic disease progression (HR 3.65, p = 0.001) were associated with worse mortality based on univariate modeling in patients treated with SSRS; on multivariate analysis, PRISM Group (HR 2.28, p = 0.03) and systemic disease progression (HR 2.67, p = 0.03) remained significant. Four patients (10%) developed compression deformity and one patient (2%) developed radiation neuritis.

CONCLUSION

SSRS provides durable local control in patients with metastatic hepatobiliary malignancies, with higher BED necessary to ensure excellent LC. PRISM scoring is a promising prognostic tool to aid SSRS patient selection.

Predictive Analytics in Spine Oncology Research: First Steps, Limitations, and Future Directions

The potential of big data analytics to improve the quality of care for patients with spine tumors is significant. At this moment, the application of big data analytics to oncology and spine surgery is at a nascent stage. As such, efforts are underway to advance data-driven oncologic care, improve patient outcomes, and guide clinical decision making. This is both relevant and critical in the practice of spine oncology as clinical decision making is often made in isolation looking at select variables deemed relevant by the physician. With rapidly evolving therapeutics in surgery, radiation, interventional radiology, and oncology, there is a need to better develop decision-making algorithms utilizing the vast data available for each patient. The challenges and limitations inherent to big data analyses are presented with an eye towards future directions.

Single-Fraction Radiotherapy (SFRT) For Bone Metastases: Patient Selection And Perspectives

Bone metastases are a frequent and important source of morbidity in cancer patients. Stereotactic body radiation therapy (SBRT) is an established treatment option for local control and pain relief of bone metastases, and it is increasingly used as upfront treatment, postoperative consolidation or salvage treatment after prior RT. However, heterogeneity of dose schedules described in literature represents a severe limitation in the definition of the role of SBRT as a standard of care. No consensus is available on the use of single versus multiple fraction SBRT for bone metastases. Advantages of single-fraction SBRT include shorter overall duration of treatment, absence of inter-fraction uncertainty, improved compliance, theoretical increased efficacy, and lower costs. However, caution has been advised due to reports of severe late toxicities, in particular, vertebral collapse fracture (VCF). The aim of this paper is to review dose fractionation and indications for the management of bone metastases using SBRT.

Stereotactic Body Radiotherapy (SBRT) for Oligometastatic Spine Metastases: An Overview

The oligometastatic state is hypothesized to represent an intermediary state of cancer between widely metastatic disease and curable, localized disease. Advancements in radiotherapy have allowed for delivery of high precision, dose escalated treatment known as stereotactic body radiotherapy (SBRT) to targets throughout the body with excellent rates of local control. Recently, the first phase II randomized trial comparing conventional radiotherapy to comprehensive SBRT of oligometastatic disease demonstrated an overall survival and progression free survival advantage. The spine is a common site of metastasis, and a complex site for SBRT given the adjacent spinal cord and the tumor embedded within the bone tissue putting the patient at risk of fracture. Although there are expert spine SBRT guidelines for practice, there are as yet no reported randomized trials that proves superiority as compared to conventional radiation. The use of SBRT in patients with oligometastatic disease and spinal metastases is the focus of this review.

Postoperative re-irradiation using stereotactic body radiotherapy for metastatic epidural spinal cord compression

OBJECTIVE

This study aimed to clarify the outcomes of postoperative re-irradiation using stereotactic body radiotherapy (SBRT) for metastatic epidural spinal cord compression (MESCC) in the authors’ institution and to identify factors correlated with local control.

METHODS

Cases in which patients with previously irradiated MESCC underwent decompression surgery followed by spine SBRT as re-irradiation between April 2013 and May 2017 were retrospectively reviewed. The surgical procedures were mainly performed by the posterior approach and included decompression and fixation. The prescribed dose for spine SBRT was 24 Gy in 2 fractions. The primary outcome was local control, which was defined as elimination, shrinkage, or no change of the tumor on CT or MRI obtained approximately every 3 months after SBRT. In addition, various patient-, treatment-, and tumor-specific factors were evaluated to determine their predictive value for local control.

RESULTS

Twenty-eight cases were identified in the authors’ institutional databases as meeting the inclusion criteria. The histology of the primary disease was thyroid cancer in 7 cases, lung cancer in 6, renal cancer in 3, colorectal cancer in 3, and other cancers in 9. The most common previous radiation dose was 30 Gy in 10 fractions (15 cases). The mean interval since the most recent irradiation was 16 months (range 5–132 months). The median duration of follow-up after SBRT was 13 months (range 4–38 months). The 1-year local control rate was 70%. In the analysis of factors related to local control, Bilsky grade, number of vertebral levels in the treatment target, the interval between the latest radiotherapy and SBRT, recursive partitioning analysis (RPA), the prognostic index for spinal metastases (PRISM), and the revised Tokuhashi score were not significantly correlated with local control. The favorable group classified by the Rades prognostic score achieved a significantly higher 1-year local control rate than the unfavorable group (1-year local control rate: 100% vs 33%; p < 0.01). Radiation-induced myelopathy and vertebral compression fracture were observed in 1 and 3 patients, respectively. No other grade 3 or greater toxicities were encountered.

CONCLUSIONS

The results indicate that spine SBRT as postoperative re-irradiation was effective, and it was especially useful for patients classified as having a good survival prognosis according to the Rades score.

Stereotactic body radiation therapy for lung, spine and oligometastatic disease: current evidence and future directions

Stereotactic body radiation therapy (SBRT) also referred to as stereotactic ablative radiotherapy (SABR), is a technique which has emerged over the past two decades due to improvements in radiation technology. Unlike conventional external beam radiotherapy (cEBRT) which traditionally delivers radiation in small doses [approximately 2 Gray (Gy) per fraction] over several weeks, SBRT, typically delivered in one to eight fractions, is a technique whereby potentially ablative doses of radiotherapy (usually 7.5-20 Gy per fraction) can be delivered with steeper dose gradients and sub millimetre precision, minimising risk to surrounding normal tissues. The potential benefits of excellent tumor control with low toxicity has led to the increasing use of SBRT in a number of clinical situations. Due to compelling evidence, SBRT is now the treatment of choice for medically inoperable patients with peripherally located stage I non-small cell lung cancer (NSCLC). Controversy remains however as to its efficacy and safety for central or ultra-central lung tumors. The evidence base supporting the use of SBRT as a novel treatment for spinal metastases and oligometastases is rapidly expanding but challenges remain in these difficult patient populations. In an era where targeted therapy and improved systemic treatments for stage IV cancer have resulted in increased disease-free survival, and our knowledge of the oligometastatic state is ever expanding, using SBRT to treat metastatic disease and gain durable local control is increasingly desirable. Several randomized trials are currently underway and are sure to provide valuable information on the benefit and utility of SBRT across many tumor sites including early-stage NSCLC, spinal metastases and oligometastatic disease. Recognizing the evolving role of SBRT in clinical practice, this paper provides a critical review of recent developments in each of these areas particularly highlighting the challenges facing clinicians and discusses potential areas for future research.

Logistic regression analysis of risk factors for postoperative recurrence of spinal tumors and analysis of prognostic factors

The aim of the present study was to investigate the risk factors for postoperative recurrence of spinal tumors by logistic regression analysis and analysis of prognostic factors. In total, 77 male and 48 female patients with spinal tumor were selected in our hospital from January, 2010 to December, 2015 and divided into the benign (n=76) and malignant groups (n=49). All the patients underwent microsurgical resection of spinal tumors and were reviewed regularly 3 months after operation. The McCormick grading system was used to evaluate the postoperative spinal cord function. Data were subjected to statistical analysis. Of the 125 cases, 63 cases showed improvement after operation, 50 cases were stable, and deterioration was found in 12 cases. The improvement rate of patients with cervical spine tumor, which reached 56.3%, was the highest. Fifty-two cases of sensory disturbance, 34 cases of pain, 30 cases of inability to exercise, 26 cases of ataxia, and 12 cases of sphincter disorders were found after operation. Seventy-two cases (57.6%) underwent total resection, 18 cases (14.4%) received subtotal resection, 23 cases (18.4%) received partial resection, and 12 cases (9.6%) were only treated with biopsy/decompression. Postoperative recurrence was found in 57 cases (45.6%). The mean recurrence time of patients in the malignant group was 27.49±6.09 months, and the mean recurrence time of patients in the benign group was 40.62±4.34. The results were significantly different (P<0.001). Recurrence was found in 18 cases of the benign group and 39 cases of the malignant group, and results were significantly different (P<0.001). Tumor recurrence was shorter in patients with a higher McCormick grade (P<0.001). Recurrence was found in 13 patients with resection and all the patients with partial resection or biopsy/decompression. The results were significantly different (P<0.001). Logistic regression analysis of total resection-related factors showed that total resection should be the preferred treatment for patients with benign tumors, thoracic and lumbosacral tumors, and lower McCormick grade, as well as patients without syringomyelia and intramedullary tumors. Logistic regression analysis of recurrence-related factors revealed that the recurrence rate was relatively higher in patients with malignant, cervical, thoracic and lumbosacral, intramedullary tumors, and higher McCormick grade and patient received partial resection or biopsy. Tumor property, tumor location, McCormick grade, tumor resection, and intramedullary tumors are risk factors for the recurrence of spinal tumors. Clinical assessment of these risk factors may be helpful in selecting appropriate treatment strategies.

An integrated multidisciplinary algorithm for the management of spinal metastases: an International Spine Oncology Consortium report

Spinal metastases are becoming increasingly common because patients with metastatic disease are living longer. The close proximity of the spinal cord to the vertebral column limits many conventional therapeutic options that can otherwise be used to treat cancer. In response to this problem, an innovative multidisciplinary approach has been developed for the management of spinal metastases, leveraging the capabilities of image-guided stereotactic radiosurgery, separation surgery, vertebroplasty, and minimally invasive local ablative approaches. In this Review, we discuss the variables that should be considered during the management of these patients and review the role of each discipline and their respective management options to provide optimal care. This work is synthesised into a practical algorithm to aid clinicians in the management of patients with spinal metastasis.

Stereotactic body radiotherapy for de novo spinal metastases: systematic review

OBJECTIVE

The aim of this systematic review was to provide an objective summary of the published literature pertaining to the use of stereotactic body radiation therapy (SBRT) specific to previously untreated spinal metastases.

METHODS

The authors performed a systematic review, using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, of the literature found in a search of Medline, PubMed, Embase, and the Cochrane Library up to March 2015. The search strategy was limited to publications in the English language.

RESULTS

A total of 14 full-text articles were included in the analysis. All studies were retrospective except for 2 studies, which were prospective. A total of 1024 treated spinal lesions were analyzed. The median follow-up time ranged from 9 to 49 months. A range of dose-fractionation schemes was used, the most common of which were 16–24 Gy/1 fraction (fx), 24 Gy/2 fx, 24–27 Gy/3 fx, and 30–35 Gy/5 fx. In studies that reported crude results regarding in-field local tumor control, 346 (85%) of 407 lesions remained controlled. For studies that reported actuarial values, the weighted average revealed a 90% 1-year local control rate. Only 3 studies reported data on complete pain response, and the weighted average of these results yielded a complete pain response rate of 54%. The most common toxicity was new or progressing vertebral compression fracture, which was observed in 9.4% of cases; 2 cases (0.2%) of neurologic injury were reported.

CONCLUSION

There is a paucity of prospective data specific to SBRT in patients with spinal metastases not otherwise irradiated. This systematic review found that SBRT is associated with favorable rates of local control (approximately 90% at 1 year) and complete pain response (approximately 50%), and low rates of serious adverse events were found. Practice guidelines are summarized based on these data and International Stereotactic Radiosurgery Society consensus.

The role of radiotherapy in bone metastases: A critical review of current literature

Radiotherapy is considered the treatment of choice for painful bone metastases. However, novel modalities of radiotherapy have emerged in the concept of oligometastasic disease. In addition, the increase of overall survival of patients with bone metastatic disease in the last decades due to systemic treatments has issued the silent topic of re-irradiation. The aim of this manuscript was to present a current thorough search of relevant literature. Originally, 6,087 articles revealed from PubMed database related to radiotherapy and bone metastases. The first objective was to identify prospective randomised phase III studies dealing with bone metastases and which treated primary with radiotherapy. Abstracts and non-English citations were excluded. Twenty-three phase III clinical trials, 17 prospective studies and eight meta-analysis/systemic reviews matching with these criteria, were identified. Eleven randomised studies were comparing single dose fraction to multi-fraction schedules of radiotherapy. The overall response rates and complete response rates were not significant between the two arms. Re-irradiations rates were significantly higher for the single dose fraction arms. Stereotactic radiotherapy showed excellent tumour control rates more than 80%. All trials showed the equivalence of either single or multi-fractionated radiotherapy for metastatic bone lesions. Stereotactic irradiation is feasible and safe for oligometastatic disease. However, it seems that the single fraction of 8 Gy is superior to 4 Gy, in terms of efficacy.

Tumor-targeted IL-12 combined with local irradiation leads to systemic tumor control via abscopal effects in vivo

NHS-IL12 is an immunocytokine, a fusion protein of IL12's functional domains and a necrosis-targeting antibody, which has shown significant effects against human rhabdomyosarcoma xenografts in a humanized tumor model, including terminal growth arrest and differentiation of the tumor cells. Here, we locally irradiated the tumors, increasing necrosis and consequently intratumoral immune cytokine availability, and asked whether this effect may surmount efficacy of single treatment modality. Humanized mice bearing bilateral rhabdomyosarcoma xenografts were evaluated for tumor burden and survival after irradiation, systemic NHS-IL12 therapy or a combination of both. Intratumoral immune compartments were characterized by immunohistochemistry and molecular methods. T_H1-cytokine dependency of underlying effector mechanisms were investigated in vitro in several human tumor cell lines. NHS-IL12 when combined with irradiation terminally arrested tumor growth and significantly improved survival. Combination treatment induced dense intratumoral T-cell infiltrates, clonal epitope-specific T-cell expansions, expression of cytotoxins, decreased pro-tumorigenic cytokines and induced senescence and differentiation in the cancer cells. Senescence and differentiation were reproduced in vitro and confirmed to be dependent on T_H1 cytokines IFNγ and TNF-α. NHS-IL12 and irradiation together induced broad intratumoral T_H1 biased NK and T-cell compartments, established antitumoral cytokine profiles and irreversibly growth arrested tumor cells, leading to systemic cancer control and improved survival. For the first time, we describe immune-induced senescence as a novel mechanism resulting from a treatment regimen combining irradiation with immunotherapy.

Stereotactic spine radiosurgery: Review of safety and efficacy with respect to dose and fractionation

BACKGROUND

Stereotactic body radiotherapy (SBRT) is an emerging treatment option for spinal metastases with demonstrated efficacy in the upfront, postoperative, and re-treatment settings, as well as for tumor histologies considered radioresistant. Uncertainty exists regarding the optimal dose and fractionation schedule, with single and multifraction regimens commonly utilized.

METHODS

A literature search of the PubMed and Medline databases was conducted to identify papers specific to spine SBRT and the effect of varying dose/fractionation regimens on outcomes. Bibliographies of relevant papers were searched for further references, and international spine SBRT experts were consulted.

RESULTS

Local control rates generally exceed 80% at 1 year, while high rates of pain control have been attained. There is insufficient evidence to suggest superiority of either single or multiple fraction regimens with respect to local control and pain control. Low rates of toxicity have been reported, assuming strict dose constraints are respected. Radiation myelopathy may be the most morbid toxicity, although the rates are low. The risk of vertebral compression fracture appears to be associated with higher doses per fraction such as those used in single-fraction regimens. The Spinal Instability Neoplastic Score should be considered when evaluating patients for spine SBRT, and prophylactic stabilisation may be warranted. Pain flare is a relatively common toxicity which may be mediated with prophylactic dexamethasone. Because of the treatment complexity and potentially serious toxicities, strict quality assurance should occur at the organizational, planning, dosimetric, and treatment delivery levels.

CONCLUSION

Both single and multifraction regimens are safe and efficacious in spine SBRT for spinal metastases. There may be advantages to hypofractionated treatment over single-fraction regimens with respect to toxicity. Ongoing investigation is underway to define optimal dose and fractionation schedules.

The use of spine stereotactic radiosurgery for oligometastatic disease

OBJECTIVE

The authors investigated the outcomes following spine stereotactic radiosurgery (SSRS) for patients with oligometastatic disease of the spine.

METHODS

The study was a secondary analysis of 38 of 209 patients enrolled in 2 separate institutional Phase I/II prospective protocols and treated with SSRS between 2002 and 2011. Of these 38 patients, 33 (87%) were treated for a solitary spine metastasis, with no other history of metastatic disease. SSRS was prescribed to 24 Gy in 1 fraction (8%), 18 Gy in 1 fraction (18%), 16 Gy in 1 fraction (11%), 27 Gy in 3 fractions (53%), 30 Gy in 5 fractions (8%), or 20 Gy in 5 fractions (3%). Seventeen patients (45%) received prior conventional external beam radiation therapy.

RESULTS

The median overall survival (OS) was 75.7 months, and the 2- and 5-year OS rates were 84% and 60%, respectively. In multivariate analysis, patients who had prior spine surgery and a better Karnofsky Performance Scale score had an improved OS (HR 0.16, 95% CI 0.05–0.52, p < 0.01, and HR 0.33, 95% CI 0.13%–0.84%, p = 0.02, respectively), and those who had undergone prior radiation therapy had a worse OS (HR 3.6, 95% CI 1.2%–10%, p = 0.02). The 1-, 2-, and 5-year local progression-free survival rates were 85%, 82%, and 78%, respectively. The median time to systemic therapy modification was 41 months. Two patients (5%) experienced late Grade 3–4 toxicity.

CONCLUSIONS

Patients with oligometastatic disease of the spine treated with SSRS can experience long-term survival and a long time before needing a modification in systemic therapy. In addition, SSRS leads to excellent local control and minimal late toxicity.

Clinical prediction model to identify vulnerable patients in ambulatory surgery: towards optimal medical decision-making

BACKGROUND

Ambulatory surgery patients are at risk of adverse psychological outcomes such as anxiety, aggression, fatigue, and depression. We developed and validated a clinical prediction model to identify patients who were vulnerable to these psychological outcome parameters.

METHODS

We prospectively assessed 383 mixed ambulatory surgery patients for psychological vulnerability, defined as the presence of anxiety (state/trait), aggression (state/trait), fatigue, and depression seven days after surgery. Three psychological vulnerability categories were considered-i.e., none, one, or multiple poor scores, defined as a score exceeding one standard deviation above the mean for each single outcome according to normative data. The following determinants were assessed preoperatively: sociodemographic (age, sex, level of education, employment status, marital status, having children, religion, nationality), medical (heart rate and body mass index), and psychological variables (self-esteem and self-efficacy), in addition to anxiety, aggression, fatigue, and depression. A prediction model was constructed using ordinal polytomous logistic regression analysis, and bootstrapping was applied for internal validation. The ordinal c-index (ORC) quantified the discriminative ability of the model, in addition to measures for overall model performance (Nagelkerke's R (2) ).

RESULTS

In this population, 137 (36%) patients were identified as being psychologically vulnerable after surgery for at least one of the psychological outcomes. The most parsimonious and optimal prediction model combined sociodemographic variables (level of education, having children, and nationality) with psychological variables (trait anxiety, state/trait aggression, fatigue, and depression). Model performance was promising: R (2)  = 30% and ORC = 0.76 after correction for optimism.

CONCLUSION

This study identified a substantial group of vulnerable patients in ambulatory surgery. The proposed clinical prediction model could allow healthcare professionals the opportunity to identify vulnerable patients in ambulatory surgery, although additional modification and validation are needed. (ClinicalTrials.gov number, NCT01441843).

Determining radiographic outcome after spine radiosurgery--not as straightforward as one might think

Spratt DE, Arevalo-Perez J, Leeman JE, Gerber NK, Folkert M, Taunk NK, et al. Early magnetic resonance imaging biomarkers to predict local control after high dose stereotactic body radiotherapy for patients with sarcoma spine metastases. Spine J 2016:16:291-98 (in this issue).